[eng] In 235, when Alexander Severus was assassinated by Maximinus the Thracian, the «crisis» started that is Characterised by military anarchy and a whole number of ensuing, interconnected crises: political-institutional, military, economic and religious. Traditionally, this period has been seen as ending with the start of Diocletian's reign in 284. Diocletian implemented a new political system known as Tetrarchy which allowed four emperors to govern at the same time but in full agreement, thanks to which the load of reforms could be more eff ectively applied which Diocletian implemented to repair the Empire. However, these reforms had a high social and political cost: a theocratic concept of power that made the emperor sacred and turned his role in governance into a divine mission.